The frontal lobes, the little brain down under and “Stayin’ Alive” (3/3)

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[Editor’s note: Con­tin­ued from Explor­ing the human brain and how it responds to stress (1/3) and On World Health Day 2020, let’s dis­cuss the stress response and the Gen­er­al Adap­ta­tion Syn­drome (2/3)]

More on the Cor­tex, the Lim­bic Sys­tem, and Stress:

The cor­tex is made up of four major sec­tions, arranged from the front to the back. These are called the frontal, pari­etal, occip­i­tal, and tem­po­ral lobes. Each of the four lobes is found in both hemi­spheres, and each is respon­si­ble for dif­fer­ent, spe­cial­ized cog­ni­tive func­tions. For exam­ple, the occip­i­tal lobe con­tains the pri­ma­ry visu­al cor­tex, and the tem­po­ral lobe (locat­ed by the tem­ples, and close to the ears) con­tains the pri­ma­ry audi­to­ry cortex.

The frontal lobes are posi­tioned at the front most region of the cere­bral cor­tex and are involved in move­ment, deci­sion mak­ing, prob­lem solv­ing, and plan­ning. There are three main divi­sions of the frontal lobes. They are the pre­frontal cor­tex, the pre­mo­tor area, and the motor area. The frontal lobe of the human brain con­tains areas devot­ed to abil­i­ties that are enhanced in or unique to humans. The pre­frontal cor­tex is respon­si­ble for plan­ning com­plex cog­ni­tive behav­iors, the expres­sion of per­son­al­i­ty, deci­sion mak­ing, and social behav­ior, as well as the orches­tra­tion of thoughts and actions nec­es­sary for a per­son to car­ry out goals. A spe­cial­ized area known as the ven­tro­lat­er­al pre-frontal cor­tex has pri­ma­ry respon­si­bil­i­ty for the pro­cess­ing of com­plex lan­guage. It is more com­mon­ly called Broca’s area, named for a nine­teenth-cen­tu­ry French physi­cian who deter­mined its role.

In humans and oth­er pri­mates, an area locat­ed at the for­ward part of the pre­frontal cor­tex is called the orbitofrontal cor­tex. It gets its name from its posi­tion imme­di­ate­ly above the orbits, the sock­ets in which the eyes are locat­ed. The orbitofrontal cor­tex is very involved in inter­pret­ing rewards, deci­sion mak­ing, and pro­cess­ing social and emo­tion­al infor­ma­tion. For this rea­son, some con­sid­er it to be a part of the lim­bic system.

The amyg­dala, a part of the lim­bic sys­tem, is a brain struc­ture that is respon­si­ble for decod­ing emo­tions, espe­cial­ly those the brain per­ceives as threats. As we evolved as a species, many of our alarm cir­cuits have been grouped togeth­er in the amyg­dala. Not sur­pris­ing­ly, many regions of the brain send neu­rons into the amyg­dala. As a result, lots of sen­so­ry mes­sages trav­el instan­ta­neous­ly to the amyg­dala to inform it of poten­tial dan­gers lurk­ing in our neigh­bor­hood. The amyg­dala is our guard dog.

The amyg­dala is direct­ly wired to the hip­pocam­pus, also a part of the lim­bic sys­tem. Since the hip­pocam­pus is involved in stor­ing and retriev­ing explic­it mem­o­ries, it feeds the amyg­dala with strong emo­tions trig­gered by these rec­ol­lec­tions. Why is this impor­tant? If a child has a neg­a­tive expe­ri­ence in school, like being ter­ri­bly embar­rassed when asked to read in front of the class, the hip­pocam­pus just won’t let go of this mem­o­ry, and it shouts it out to the amyg­dala. Since the amyg­dala has signed a no con­fi­den­tial­i­ty agree­ment, it sends a warn­ing to the rest of the brain to go into pro­tec­tion mode. A rather amaz­ing arrange­ment, don’t you think?

What’s real­ly inter­est­ing about this is that the hip­pocam­pus spe­cial­izes in pro­cess­ing the con­text of a sit­u­a­tion. As a result, the child (or adult) under stress gen­er­al­izes the entire sit­u­a­tion and uses it as jus­ti­fi­ca­tion for anx­i­ety or stress: “Hey, they’re telling me to go to social stud­ies class.” Even though not every­thing about social stud­ies may be a threat — per­haps just the fact that they read out loud in there — the hip­pocam­pus sends out a gen­er­al alert. So the stu­dent responds by protest­ing the whole enchi­la­da: “No way I’m going there.”

The amyg­dala is also wired to the medi­al pre­frontal cor­tex. Want to know why this is impor­tant? This is the area of the brain that seems to be involved in plan­ning a spe­cif­ic response to a threat to safety.

Here’s how it works: the child is hit with the gigan­tic Titan­ic news (which may be just “social stud­ies com­ing up next” to the rest of the group, but it’s “Sub­merged ice­berg ahead!” to the stu­dent wor­ried about per­ceived hor­rors there). This two-way  com­mu­ni­ca­tion between the pre­frontal cor­tex and the lim­bic sys­tem (par­tic­u­lar­ly the amyg­dala) enables us to exer­cise con­scious con­trol over our anx­i­ety. The emo­tion — cog­ni­tion con­nec­tion allows us to feel that we can do some­thing about the dan­ger that lies ahead. The child is then faced with the neces­si­ty of choos­ing a course of action that looks best for get­ting out of dan­ger. This seems very pro­tec­tive but tends to be coun­ter­pro­duc­tive, because the very mech­a­nism that allows us to cre­ate an escape plan can actu­al­ly cre­ate anxiety.

The brain not only allows us to imag­ine a neg­a­tive out­come, which can help us avoid dan­ger, it makes it pos­si­ble for us to imag­ine dan­gers that do not actu­al­ly exist.

The Thal­a­mus Bone:

Of course, it’s not real­ly a bone; it’s a plum — shaped mass of gray mat­ter that’s mul­ti­lay­ered and mul­ti­fac­eted. The thal­a­mus, anoth­er part of the lim­bic sys­tem, sits on top of the hypo­thal­a­mus which, in turn, sits on top of the brain stem, which is in the cen­ter of the base of the brain. This is a great loca­tion for the thal­a­mus because it acts as a relay sys­tem that sends nerve fibers upstairs to all parts of the cere­bral cor­tex as well as many sub-cor­ti­cal (under­neath the cor­tex) parts of the brain. The thal­a­mus receives infor­ma­tion from every sen­so­ry organ and its asso­ci­at­ed neu­rons except the olfac­to­ry (smell) sys­tem. The hypo­thal­a­mus gets infor­ma­tion from the eyes, the ears, the skin, and the tongue, and it for­wards these mes­sages to the cor­re­spond­ing areas of the cor­tex where they are processed. In terms of stress, this relay sys­tem is how the brain knows that it’s in a dan­ger­ous environment.

The Lit­tle Brain Down Under:

Sit­ting under the occip­i­tal and tem­po­ral lobes of the brain is the cere­bel­lum. It’s about the size of a child’s fist. Because it looks like a sep­a­rate brain­like struc­ture attached to the under­side of the cor­tex, the cere­bel­lum is some­times referred to as the “lit­tle brain.” It’s con­nect­ed to the brain stem, which in turn con­nects the brain to the spinal cord. The cere­bel­lum used to be rel­e­gat­ed to the very sim­ple role of help­ing us main­tain bal­ance when we walk or run, but mod­ern neu­ro­science has found that the cere­bel­lum plays a much larg­er and more impor­tant role than that.

Like the hypo­thal­a­mus, it is involved in cog­ni­tive func­tions, includ­ing atten­tion and lan­guage, as well as the abil­i­ty to hold men­tal images in the “mind’s eye.” This part of the brain is impor­tant to the dis­cus­sion of stress, since recent research has shown that the cere­bel­lum also plays a key role in reg­u­lat­ing respons­es to plea­sure and to fear — strong forces when it comes to lov­ing what’s next in our sched­ule or hat­ing it.

The Bee Gees song “Stayin’ Alive” reached #1 on the pop charts in 1977. Maybe it was the beat, maybe it was John Travolta’s danc­ing. Or maybe it’s that the Gibb broth­ers’ cen­tral lyric is quite lit­er­al­ly always play­ing in our head. Keep­ing us safe —that is, “stayin’ alive ”— is the pri­ma­ry mis­sion of the brain. The brain works very fast and very hard —most­ly in the back­ground— to do just that. It’s exquis­ite­ly posi­tioned close to ears, eyes, nose, and mouth so the sig­nals from those sen­so­ry organs get into it with­out delay. Every­thing we encounter in our dai­ly lives gets sent, incred­i­bly fast, from our ears, nose, mouth, skin, and eyes to our brain for pro­cess­ing. The brain con­trols the oth­er organ sys­tems of the body, either by acti­vat­ing mus­cles or by caus­ing secre­tion of chem­i­cals such as hor­mones. That three-pound mass of gray and white mat­ter some­what mirac­u­lous­ly uses this unend­ing and poten­tial­ly over­whelm­ing stream of infor­ma­tion to change our phys­i­cal posi­tion, our pat­tern of thought, and our feel­ings or emo­tions — all in the ser­vice of keep­ing us alive. After all, a brain with­out a body is, if you will for­give me, nobody at all.

Now that you have had an intro­duc­tion to this mar­velous and com­plex organ called the brain, it hope it will eas­i­er to under­stand what hap­pens to the brain under stress, and how to cope with it.

– Dr. Jerome (Jer­ry) Schultz is a Clin­i­cal Neu­ropsy­chol­o­gist, author and speak­er who has pro­vid­ed clin­i­cal ser­vices, con­sul­ta­tion and staff devel­op­ment to hun­dreds of pri­vate and pub­lic schools in the US and abroad dur­ing his 35-year career. This is an adapt­ed excerpt from his lat­est book Nowhere to Hide: Why Kids with ADHD & LD Hate School and What We Can Do About It, which exam­ines the role of stress in learning.

Resources to regulate stress:

Four tips to prac­tice good men­tal hygiene dur­ing the coro­n­avirus outbreak

Study finds a key ingre­di­ent in mind­ful­ness train­ing: Accep­tance (not acquiescence)

Pos­i­tive soli­tude, Feel­ing active and Future-mind­ednes: Three Keys to Well-being

New study rein­forces the impor­tance of walk­ing through forests for men­tal and gen­er­al health

Six tips to build resilience and pre­vent brain-dam­ag­ing stress